Peer-to-peer (P2P) technology has generated a revolution in the area of network communication and continues drawing more and more attention. P2P computing provides an alternative to the traditional client/server network architecture. In a P2P network, each peer node, such as a computer, works as a client or as a server within the context of a given application. P2P applications build functions such as storage, computation, messaging, security, and file distribution, through direct exchanges between peer nodes. A peer node may initiate requests and may respond to requests from other peer nodes in the network. P2P technology provides many benefits to network communications, such as broader sharing scope of information and efficient utilization of network resources.
Though P2P technology is demonstrated to be extremely promising, several issues remain unsolved. One of the problems is that P2P applications that originate from different sources are usually not interoperable with one another, and each may have its own set of basic services and plug-ins. A more significant problem is that developers of new P2P applications cannot readily benefit from the experience of other P2P developers. Therefore, all the developers of new P2P applications have to pretty much start from setting up their own P2P network and building up their own libraries, which may have been successfully accomplished before by others already. Such efforts wasted in repetition could be better spent in developing features and functionality for new applications.
Besides the interoperability issue, there are other concerns about P2P networks, for example, peer nodes may be infected by virus or malwares contained in data shared; contents shared between peer nodes may not have authentic digital copyright management (DRM) information.